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AC Clutch not engaging without jumping


acreature

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Hypothetically, just boil the can to get the pressure up?
 


RonD

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The 12v runs from pressure switch to pressure switch then to relay base, then to AC Compressor

First pressure switch is at the accumulator, you said you had 12v there on 1 wire with AC switch ON
If you put that connector back on that pressure switch then next pressure switch should have 12v, not sure where that pressure switch is on your 1996, you have to look for it.

It will be on an AC line and have two wires like the first one, 12v IN and 12v OUT if pressure switch is OK

If the nest pressure switch does NOT have 12v then the first one is OPEN, not passing the 12v
 

Denisefwd93

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No dont boil! just hot water from the tap is all you need, you can actually warm the small cans with your hands.
 

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The compressor needs OIL circulating or it will burn out, the oil is in the "freon", the pressure switches are there to prevent system from "blowing up" i.e. high pressure from blockage, and from low pressure i.e. low "freon" levels which would burn out compressor from lack of oiling.
To this point it is also extremely important to note that PAG does not mix into R-134a the same way that ester oil mixed into R12. R12 had the ability to mix with the oil and become a lubricant itself, carrying to oil through the system. R-134a does not have that ability and instead it pushes the oil through the system. Not enough refrigerant and the oil collects in the accumulator and can't move back to the compressor. This is why it is so important that R-134a systems be charged properly.

It is also why I don't trust those cans that say they already have the oil in them, it doesn't stay mixed, and so it is very hard to be sure you are putting the correct amount of oil in.
 

acreature

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The 12v runs from pressure switch to pressure switch then to relay base, then to AC Compressor

First pressure switch is at the accumulator, you said you had 12v there on 1 wire with AC switch ON
If you put that connector back on that pressure switch then next pressure switch should have 12v, not sure where that pressure switch is on your 1996, you have to look for it.

It will be on an AC line and have two wires like the first one, 12v IN and 12v OUT if pressure switch is OK

If the nest pressure switch does NOT have 12v then the first one is OPEN, not passing the 12v
That makes sense. Thanks. I'll look into that when I can.
 

acreature

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The 12v runs from pressure switch to pressure switch then to relay base, then to AC Compressor

First pressure switch is at the accumulator, you said you had 12v there on 1 wire with AC switch ON
If you put that connector back on that pressure switch then next pressure switch should have 12v, not sure where that pressure switch is on your 1996, you have to look for it.

It will be on an AC line and have two wires like the first one, 12v IN and 12v OUT if pressure switch is OK

If the nest pressure switch does NOT have 12v then the first one is OPEN, not passing the 12v
First pigtail has 12v. Plug that pressure switch back in and there is no 12v at the second pigtail/pressure switch.

Is there a test - resistance# I should check on the first pressure switch or is this just a replace the part scenario?
 

Denisefwd93

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Just remember liquid = (can upside down) only goes in the high side which is the smaller high pressure line coming off the compressor into the condenser the low side is from the orifice to the back of the compressor on the larger line where you do not want to put liquid. if you are feeling cautious about messing with liquid refrigerant you can put vapor (can right side up) in either side but it will take continuous warming of the refrigerant cans.

as you can see on my replacement lines the muffler has a connection for the high pressure switch, this is often confused for the high side port. when it's not hooked up on replacement lines. [emoji848] (Some people take months and months before they get around to connecting the high pressure switch that they forgot to pick up when they ordered the hoses)

 
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RonD

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First pigtail has 12v. Plug that pressure switch back in and there is no 12v at the second pigtail/pressure switch.

Is there a test - resistance# I should check on the first pressure switch or is this just a replace the part scenario?
Its a Pressure switch, so should be 0 OHMS if there is GOOD pressure in the system.
High OHMs or N/C(no connection) if pressure is too low or too high, depending on what switch is reading.

Pressure switches can fail, but you determine that by hooking up pressure gauges to the AC system, reading the actual pressure in the system will tell you if a pressure switch has failed
 

acreature

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Its a Pressure switch, so should be 0 OHMS if there is GOOD pressure in the system.
High OHMs or N/C(no connection) if pressure is too low or too high, depending on what switch is reading.

Pressure switches can fail, but you determine that by hooking up pressure gauges to the AC system, reading the actual pressure in the system will tell you if a pressure switch has failed

Will removing that switch on the condenser cause freon to be released, or is it safe to remove myself?
 

Denisefwd93

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Far as I know, all the automotive pressure switches have Schrader depressors inside the connection. I just don't think you should tear into the system until you charge it or have it charged up if you only have 12 lb pressure. It's definitely low - almost zero refrigerant
 

RonD

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Yes, pressure switches can be changed without draining and recharging the system, but again, you can only tell if a switch is bad after connecting pressure gauges to the system.

So don't remove them until then
 

acreature

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Yes, pressure switches can be changed without draining and recharging the system, but again, you can only tell if a switch is bad after connecting pressure gauges to the system.

So don't remove them until then
Point taken.

My local Vatozone doesn't loan out the gauges. I will check around.
 

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